Hudson is missing its subversionSCM.xml file?

Hi there.
Hudson newbie here with a simple question.

I'm trying to get the Subversion Tagging Plugin whipped into shape
(http://hudson.gotdns.com/wiki/display/HUDSON/Subversion+Tagging+Plugin).
I've got my sample project up, and everything builds fine until it
comes to the tagging part. I get errors about a missing
hudson.svm.SubversionSCM.xml file.

I stumbled across a CVSSCM.xml file under the hudson root and naively
thought I could bend it into shape, but that didn't work out too well.
Hudson pukes out a stacktrace indicating an NPE at
hudson.plugins.svn_tag.SvnTagPlugin.perform(SvnTagPlugin.java:188).

Any advice on using hudson to generate this file, or of finding a
sample xml or a valid xsd so I can put the proper parameters here?

Thanks much for any help.
- Mark